lkml.org 
[lkml]   [2019]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v9 19/22] RISC-V: KVM: Remove per-CPU vsip_shadow variable
Date
Currently, we track last value wrote to VSIP CSR using per-CPU
vsip_shadow variable but this easily goes out-of-sync because
Guest can update VSIP.SSIP bit directly.

To simplify things, we remove per-CPU vsip_shadow variable and
unconditionally write vcpu->arch.guest_csr.vsip to VSIP CSR in
run-loop.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
arch/riscv/include/asm/kvm_host.h | 3 ---
arch/riscv/kvm/main.c | 6 ------
arch/riscv/kvm/vcpu.c | 24 +-----------------------
3 files changed, 1 insertion(+), 32 deletions(-)

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index ec1ca4bc98f2..cd86acaed055 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -202,9 +202,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}

-int kvm_riscv_setup_vsip(void);
-void kvm_riscv_cleanup_vsip(void);
-
#define KVM_ARCH_WANT_MMU_NOTIFIER
int kvm_unmap_hva_range(struct kvm *kvm,
unsigned long start, unsigned long end);
diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
index 55df85184241..002301a27d29 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -61,17 +61,11 @@ void kvm_arch_hardware_disable(void)

int kvm_arch_init(void *opaque)
{
- int ret;
-
if (!riscv_isa_extension_available(NULL, h)) {
kvm_info("hypervisor extension not available\n");
return -ENODEV;
}

- ret = kvm_riscv_setup_vsip();
- if (ret)
- return ret;
-
kvm_riscv_stage2_vmid_detect();

kvm_info("hypervisor extension available\n");
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index fd77cd39dd8c..f1a218d3a8cf 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -111,8 +111,6 @@ static void kvm_riscv_vcpu_host_fp_restore(struct kvm_cpu_context *cntx) {}
riscv_isa_extension_mask(s) | \
riscv_isa_extension_mask(u))

-static unsigned long __percpu *vsip_shadow;
-
static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
@@ -765,7 +763,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
- unsigned long *vsip = raw_cpu_ptr(vsip_shadow);

csr_write(CSR_VSSTATUS, csr->vsstatus);
csr_write(CSR_VSIE, csr->vsie);
@@ -775,7 +772,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
csr_write(CSR_VSCAUSE, csr->vscause);
csr_write(CSR_VSTVAL, csr->vstval);
csr_write(CSR_VSIP, csr->vsip);
- *vsip = csr->vsip;
csr_write(CSR_VSATP, csr->vsatp);

kvm_riscv_stage2_update_hgatp(vcpu);
@@ -843,26 +839,8 @@ static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu)
static void kvm_riscv_update_vsip(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
- unsigned long *vsip = raw_cpu_ptr(vsip_shadow);
-
- if (*vsip != csr->vsip) {
- csr_write(CSR_VSIP, csr->vsip);
- *vsip = csr->vsip;
- }
-}
-
-int kvm_riscv_setup_vsip(void)
-{
- vsip_shadow = alloc_percpu(unsigned long);
- if (!vsip_shadow)
- return -ENOMEM;

- return 0;
-}
-
-void kvm_riscv_cleanup_vsip(void)
-{
- free_percpu(vsip_shadow);
+ csr_write(CSR_VSIP, csr->vsip);
}

int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
--
2.17.1
\
 
 \ /
  Last update: 2019-10-16 18:13    [W:0.160 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site